MSBuild-compatible build system for Mono

Mono is a platform for running and developing applications based on the
ECMA/ISO Standards. Mono is an open source effort led by Novell.
Mono provides a complete CLR (Common Language Runtime) including compiler and
runtime, which can produce and execute CIL (Common Intermediate Language)
bytecode (aka assemblies), and a class library.

xbuild is Mono's implementation of msbuild and allows projects that have a
msbuild file to be compiled natively on Linux.

Microsoft Build (msbuild) is a build system developed by Microsoft similar in
spirit to Nant (in that it uses XML files for describing the build process)
and in the same spirit as make.